Dyes and dyeing



Patented June l2, 1934 UNITED STATES DYES AND DYEING David Alexander Whyte Fairweather and John Thomas, Grangemouth, Scotland, assignors to Scottish Dyes, Limited, Grangemouth, Scotland No Drawing. Original application March 5, 1930, Serial No. 433,498. Divided and this application August 20, 1931, Serial No. 558,418. In Great Britain March 7, 1929 9 Claims.

As a result of researches we have found among other things that in the oxidation of Z-aminol anthra-hydroquinoire-Q:10-disulphuric acid .es-

ter in alkaline mediafit is possible to obtain and isolate a body which appears to be the tetra sulphuric acid ester of tetrahydro indanthrone.

This is a very sensitive body which, in contact 15. with acid is converted to a reddish-violet substance, and this reddish violet substance appears to be the known disulphuric acid ester of dihydro indanthrone. I

We have also discovered'that the tetra sulphuric ester can be used for dyeing textile fibres c and the like, development or fixation being effected for instance by hydrolysis and oxidation on the fibre, for example, by acid solutions of ferric chloride, cupric chloride, or other known methods for the development or fixing or sulphuric acid esters of vat dyestuffs.

This tetra sulphuric ester appears to have an advantage over previously described esters of.

As the tetra-ester is so sensitive to acid it cannot readily be isolated by means of acid, but may conveniently be isolated by precipitating withpotassiumchloride or other suitable salt. It can also be isolated by evaporation of the alkaline solution. Alternatively it can be salted out or evaporated from neutral solution. ,7

In addition to the ester of 2-amino-anthrahydroquinone, substituted derivatives may be used, including those in which one of the hydrogen atoms of the amino group is replaced, but excluding those which have the substituent in the alpha position adjacent to the amino group.

The esters obtained from these substituted bed- 4 iesappear to be tetra-esters, and we have found that they may be usedin the same way as the tetra-ester obtained from the ester of amino-anthra-hydroquinone.

Further to the above, we have found that in the alkaline oxidation of the dsulphuric ester of the amino-anthra-hydroquinone of commercial pm'ity it is possible to take the solution of the ester obtained after oxidation, and to separate it.

into one or more products. By this means we oband has the advantage that it gives brilliant blue dyeings on the fibre; in fact, dveings can be obtained equal in brightness to those obtained from specially purified dianthraquinone-l :2 2' 1'-dihydroazine. The purification is preferablyeffected so by a fractional crystallization, and we have found the potassium salts very suitable for this purpose.

By the methods of isolation from the yellow solutions obtained by alkaline oxidation of amino-anthra-hydro-quinone-9-10 disulphuric as acid ester or its substituted derivatives of solid yellow crystalline bodies, presumably sulphuric acid esters of dianthraquinonyl-l:2:l'-2'-dihydroazine or its. derivatives, small quantities of impurities unavoidably remain in .the product. To The presence ofthese impurities is not greatly detrimental to the brightness of shade on cotton, but tends to produce dull shades on animal fibres. We have found that these impurities may be removed by means of a solvent such as methyl or ethyl alcohol in which theimpurities are soluble but the required product is insoluble. This result is unexpected, as the by-products which are themselves presumably potassium salts of sulphuric acid esters, are some less soluble and some more so soluble in water than the yellow ester itself.

The invention consists in the process which comprises the employment of a tetra-ester of tetra-hydro-indanthrone or of a substituted indanthrone, for example, the tetra-ester from at 2-amino-anthra-hydroquinone 9: 10 disulphuric acid ester or a substituted body of the aforesaid tetra-sulphuric acid ester in the parts of dyeing and the like. I

The invention also consists in the process so which comprises the application of products such as may be prepared as indicated above or by the equivalents of those processes especially when so prepared to the dyeing or colouration' of textile fibres or the like for instance by hydrolysls and oxidation preferably in the presence of acid. F

The invention also consists in dyed "or otherwise ooloured materials such as may be obtained by the use of products according to or prepared according to the processes indicated herein, or their equivalents, especially when so prepared.

The following examples illustrate how the inr vention may becarried into eii'ect, Examples 1. 2, 3, 5, 6, 'l, 8, 9, 10, 11, 13, 14, 15, 16, 1'7 and 20 being examples showing methods of preparation of vat dyestufl' derivatives which may be utilized according to the present invention, and the remaining examples, namely Examples 4, 12, 1a, 19, no

21, 22 and 23 giving methods of utilizing the products for the purpose of the present invention, references to parts and to percentages being to parts and percentages by weight:

Example 1 This deals with a method of preparing what appears to bethe tetra sulphuric ester of tetra hydroindanthrone.

42.9 parts of sodium salt of B-amino-anthrahydroquinone disulphuric acid ester are dissolved in water together; with 5 parts caustic soda, and

a solution containing 7.4 parts sodium hypochlorite added slowly at 15 C. with stirring and cooling. The resulting solution contains what has been referred to above as the tetra sulphuric acid ester of tetra hydroindanthrone, also to be called the tetra sulphuric ester of tetra-hydrodianthraquinone-azine.

Example 2 A solution prepared as in Example 1 is evaporated until a concentrated solution is obtained and the solution saturated with potassium chlo- The precipitate which forms is filtered off.

I Example 3 Instead of isolating by the method of Example 2 the solution may be completely evaporated to dryness.

Evaporation can be carried out under ordinary pressure or preferably under vacuum or spray drier.

Example 4 According to this example, padding of cotton or the like is carried out by means of the solution obtained in Example 1, or in a solution made by redissolving the products of Examples 2 and 3 andthen immersing the padded material in an acid oxidizing bath.

The strength of ester solution employed may be about one part of ester in about twenty parts of water, the material preferably being dried and then developed at 85 C. 'in a solution of 1 per cent. hydrochloric acid and 2 per cent. crystalline copper sulphate, 10 per cent.

of salt being employed if desired.

Example 5 Example 6 Instead of adding sodium hypochlorite liquor as in the previous example, the hypochlorite may be formed in situ by passing into the liquor, to which has been added an additional 103 parts of caustic soda, 91 parts of chlorine at a temperature of 0.-5 C.

Example 7 This is an example of the use of a sulphuric ester of a substituted p-amino-anthraquinone.

Example 8 The solution obtained in Example 7 may be salted out by the addition of 40 to 50 per cent.

of potassium carbonate and the paste obtained by filtration used for dyeing after dissolving in water.

Example 9 This describes the production of a solution of the yellow body.

46 parts of the potassium salt of e-aminoanthrahydroquinone disulphuric acid ester are dissolved in water together with 5 parts of caustic soda and then a solution containing 7.4 parts of sodium hypochlorite is slowly added at 15 C. with good stirring and cooling so that the temperature does not rise above the 15 C.

Example 10 This is an example of the separation of the pure material from the product obtained in Example 9. The solution from this example is evaporated until its mass is reduced to about 600 parts (alternatively the amount of water used in Example 9 may be chosen so that no evaporation is necessary) When the mass of the solution is correct, sufficient potassium chloride is added until the solution contains about 75 parts of potassium. The liquor is cooled and filtered. The filtrate is then saturated with potassium chloride and allowed to stand for several hours when the yellow ester is precipitated in crystalline form and of high purity. These crystals are filtered off and sucked dry.

Example 11 This example describes a modified method of isolating the pure product.

After evaporating the solution, as already described in Example 10, this solution is saturated with potassium chloride while hot. After saturation it is filtered at a temperature of '7080. By this means the by-products of less solubility remain behind. The filtrate is allowed to cool,

when a thick brown precipitate separates, which is filtered off and sucked dry as before.

Example 12 Example 13 i The liquor obtained as in Example 5 is treated with 1000 parts of potassium chloride and filtered cold, the residue being washed with saturated potassium chloride solution. To the combined washings and filtrate is added a further 1000 parts of potassium chloride. The precipitate that separates on cooling is filtered oil.

Example 14 This in an example of the further purification I of the product obtained in Examples 2, 3 and 13. The dyestuff paste is dissolved in suill cient water to allow of complete solution at about 50 C. It is filtered from any foreign matter and reprecipitated by the addition of potassium chloride or potassium carbonate. The paste is washed on the filter with saturated potassium chloride.

\ Example 15 The yellow crystalline product obtained as in Examples 10 and 11 above is dried and extracted continuously with methyl alcohol until no further material is dissolved out. The residue is yellow in colour and consists of the starting material in a stateof very high purity. The alcoholic liquor contains almost none of this product.

Example 16 Instead of drying the material before extraction as in the preceding example, the damp ester may be washed on the filter with alcohol or alternatively stirred to a paste with alcohol and filtered.

It should be noted that the processes of the above three examples are only designed to remove impurities which may dullthe shade of dyeings and that inorganic salts may remain in the final product, these having no deleterious effect.

Example 18 acetic acid. The dyeing is developed in a bath containing 2 per cent. copper sulphate and 2 per cent. concentrated hydrochloric acid at about C. Development is complete in a few minutes.

Example 19 This is a modification of the preceding example in which an amount of salt equal in weight to the wool is added to the dyebath. The wool is dyed a bright yellow and is developed as above.

Example 20 To the oxidized liquor obtained as in Example 7 is added 25 per cent. of its weight of potassium chloride. The matter is stirred for several hours in the cold and filtered, the cake being washed.

with a saturated solution of potassium chloride. To the combined filtrates and washings is now added 15 per cent. of sodium hydroxide, sodium carbonate, potassium hydroxide or potassium carminutes 'at 87 C. and soaped at the boil.

bonate, and the liquid allowed to stand 12 hours at ordinary temperature; It is then filtered and the cake is lifted and is stirred at 60 C. with 650 parts of ethyl alcohol for one hour.

On cooling, what is presumably the tetra ester 8 of dichlor tetra hydro indanthrone crystallizes out in pure form. It is filtered off and washed on the filter with cold ethyl alcohol until the runnings are nearly colourless.

Example 21 A padding bath is made up from 54 parts of water, 54 parts. of 30 percent. sodium chloride solution and 10 parts of a 12 per cent. paste of the very pure tetra ester of indanthrone obtained 90 by the methods of Examples 15, 16- or 17. The r I cotton is then padded in this, squeezed and dried in warm air. It is then developed in a bath containing 2 per cent. of copper sulphate crystals and 1 per cent. concentrated hydrochloric acid for 4 Example 22 Scoured woolen cloth of dry weight equivalent i to 13 parts is thoroughly wetted out and entered at 40 G. into a bath made by dissolving 2.75 parts of a 16 per cent. paste of the pure potassium salt of the tetra sulphuric ester of dichlor indanthrone.

The temperature'is raised to 90-95 C. while working the wool and a 5 per cent. solution of acetic acid is then slowly added and the material worked until the dy'estuii is all absorbed and the .bath becomes colourless.

The dyeing is then transferred'to a bath containing 2 per cent. of cupric sulphate crystals and 2 per cent. of concentrated hydrochloric acid at 87 C. and developed at this temperature for a few minutes.

Example 23 20 parts of dark British gum powder and 10 parts of glycerine are boiled upwith 70 parts of water and then cooled and 5 parts of a 20 perpent. paste of the ester are stirred in.

After printing the goods are steamed and developed.

General The invention is not limited to the examples given above, nor is it confined to the use of esters of indanthrone, but may be applied in connection with other vat dyestufi's. The chemically equivalent quantity oi the potassium salt of p-amino-, anthra-hydroquinone disulphuric acid ester may be used in Example 1 in place of the sodium salt referred to therein, and the resulting product employed instead of the product of Example 1.

Where reference has been made to dyeing, this includes printing, padding, pigmenting or otherwise colouring.

Some of the products obtained'by the process of separation referred to above do not give a blue vat dyestufi under the conditions described. That residue which crystallizes out first does so in the form of brownish crystals. The filtrate remaining after separating the pure body is also brown in colour, and contains material of high solubility.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is:-

1. The process which consists in the application y of dyeing purposes of bodies. selected from the group consisting tetra-sulphuric esters of (a) tetra-hydro-indanthrone an substituted tetra-hydro-indanthrones.

2. A process for the colouration of textile materials and fibres which consists in the application to the material to be coloured of a tetra-sulphuric ester of a tetra hydro-clianthraquinone-azine in which the ester groups are in 9: 10 positions followed by development of the colour.

3. A process for the colouration of textile materials and fibres which consists in the application to the material to be coloured of a tetra-sulphuric ester of a tetra-hydro-dianthraquinone-azine in which the ester groups are in 9:10 positions followed by treatment of the material with an acid.

4. A process for the colouration of textile materials-and fibres which consists in the application to the material to be coloured of a tetra-sulphuric ester of a tetra-hydro-dianthraquinone-azine in which the ester groups are in 9:10 positions followed by treatment of the material with an acid in the presence of a. copper salt.

r 5. A process for the colouration of textile materials and fibres which consists in the application to the material to be coloured of the tetra-sulphuric ester of 3:3'-dichloro-tetra-hydro-dianthraquinone -azine in which the ester groups are in 9:10 positions followed by development of the colour.

6. A process as claimed in claim 3, in which cotton is the textile material and fibre to be coloured.

'7. A process as claimed in claim 3, in which wool is the textile material and fibre to be coloured.

8. A process as claimed in claim 4, in which cotton is the textile material and fibre to be coloured.

9. A process as claimed in claim 4, in which wool is the textile material and fibre to be coloured. DAVID ALEXANDER WHYTE FAIRWEATHER. JOHN THOMAS. 

